U. S. Pat. No. 4,633,597, entitled "Elastic Pressure and Automatic-air-ventilation Type of Insole" disclosed by the same inventor of this application, taught an elastic air-sack type of insole adapted for making the air inside the shoes circulated by means of restoring effect of the air sack, which however has the following defects:
1. The air sack insole is made of an elastic film piece being closely attached to the edge of a flat insole, for instance, the air sack being made as a curved form closely pressed and fastened to an edge of the insole, which thereby increases the production inconvenience and cost since further pressing or fastening steps must be done for its processing.
2. The ventilating air intake and exhaust valves are formed on two sides of the insole, not highly formed on the shoe vamp, thereby influencing their sound ventilation, especially influencing the exchange of fresh air with the environmental air.
3. The front air orifices are generally formed on a front edge of the insole, which however if being cut for reducing its size for the snugly wearing by a user, the air ventilation effect will be greatly reduced so that the size of the insole must be predetermined, not suitable for a user's optional adjusting.
The present inventor has found the defects of his previous invention and invented the present insole-ventilating shoe.